39
PT UNIT USER MANUAL
APRIL 2023 www.eaton.com.cn
Appendix A - Modbus Communication Port Setting
A.3.6 Configuration Registers
Non-volatile register 402001/425345 (0x07D0
16
/0x6300
16
) is
used to configure the trip unit to respond to a group of data
objects, of which some objects are invalid within that group.
When non-zero (default value), any attempt to access a group
of data objects that contain an invalid object will result in an
illegal data object code 02. When register 402001/425345
(0x07D0
16
/0x6300
16
) is set to zero, the trip unit will respond
to a group of objects with data contained in the valid objects
of the group along with an illegal value (if available), or else
000016 data contained in the invalid objects.
Non-volatile register 402002/425346 (0x07D1
16
/0x6301
16
)
is used to configure the data transmission order of 32-bit
floating point data. If non-zero (default value), the floating-
point low order word is first in the Modbus register space.
When the register is set to be 0, the floating-point high
order word is first in the Modbus register space. Non-volatile
register 402003/425347 (0x07D2
16
/0x6302
16
) is used to
configure the data transmission order of 32-bit fixed point
data. If non-zero (default value), the fixed-point low order
word is first in the Modbus register space. When the register
is set to be 0, the fixed-point high order word is first in the
Modbus register space.
To accommodate Modbus master that can access up to
register 9999, some Eaton registers initially assigned above
9999 have been assigned dual access, both at the original
register (to provide compatibility) and at a new register
assignment below 9999. The format is given as low/high
register numbers followed by (low16/high16 Modbus register
addresses). An example is: 4xxxx/4yyyyy (XXXX+1
16
/YYYY+1
16
).
Table 10. Configuration Registers
Register
Definition
R/W
Modbus Register
Number
Modbus Register
Address
Number
Mapped block
of registers
configuration
R/W
401001/420481
0x03E8/0x5000
100
Mapped block of
registers data
R
401201/420737
0x04B0/0x5100
100*2
Invalid
object access
configuration
R/W
402001/425345
0x07D0/0x6300
1
Floating point
data word order
R/W
402002/425346
0x07D1/0x6301
1
Fixed point data
word order
configuration
R/W
402003/425347
0x07D2/0x6302
1
Remote control
R/W
402901/425089
0x0B54/0x6200
3
Date and time
register
R/W
402921
0x0B68
8
A.3.7 Remote Control
A set of registers is used for the trip unit remote control,
starting from 402901/425089 through 402903/425091.
These three registers should be written together with a “slave
action number” and its first complement using function code
16. The data format registers are shown as Figure A2. The
“slave action number” and its function are listed in Table A11,
their support being product dependent.
If the “slave action number" and its first complement
command is valid, the trip unit will execute the action. Once
the command is successfully acknowledged by the trip unit,
it returns a normal function code 16 response to Modbus
master. Since it may take some time for the trip unit to
act, Modbus master may further determine if the product
completed the slave action function successfully after the
normal response. If the “slave action number” and its first
complement command is invalid, the trip unit returns
exception code 03.
Figure A2. Remote Control Data Format
